Calls are the options of choice on SINA in today's session

Both call and put volume are accelerated on SINA Corp (NASDAQ:SINA - 49.23) in today's session, trading at more than two times their respective intraday volumes. By the numbers, calls have the slight edge, with roughly 26,000 contracts having crossed the tape at last check. Meanwhile, around 17,000 puts have changed hands.

SINA's out-of-the-money 52.50 strike is in high demand, with nearly 4,000 contracts crossing at the December call, and about 2,000 contracts trading at the 11/23 weekly call. The majority of the contracts at each position have changed hands at the ask price, implied volatility has ticked higher, and volume is easily outstripping open interest. In other words, it's safe to assume new positions are being initiated.

By buying to open the December 52.50-strike call for a volume-weighted average price (VWAP) of $1.94, traders will profit with each step north of $54.44 (the strike plus the premium paid) SINA takes through December expiration. Meanwhile, the weekly 52.50-strike call will turn profitable should the stock conquer the $52.96 mark (the strike plus the VWAP of $0.46) by week's end. These breakeven levels represent a respective 10.6% and 7.6% jump from the equity's current perch.

Widening the scope, it appears calls have been quite popular in SINA's options pit. At the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), traders have bought to open 2.51 calls for every put during the past 10 sessions. What's more, this call/put volume ratio ranks higher than 87% of other such readings taken in the past year, suggesting calls have been bought to open over puts at a faster-than-usual clip in recent weeks.

Echoing this trend is the equity's Schaeffer's put/call open interest ratio (SOIR) of 0.49. Not only does this show call open interest more than doubles put open interest among options expiring in three months' time, but it ranks in the 8th percentile of its annual range. Simply put, short-term speculators have rarely been more call-heavy toward SINA.

On the charts, SINA has had its fair share of struggles. Heading into today's session, the stock was sitting on a dreary 39.2% year-over-year deficit. Plus, over the last 40 sessions, the equity has underperformed the broader S&P 500 Index (SPX) by more than 27 percentage points. Highlighting this downward trajectory has been SINA's 10- and 20-day moving averages, which have ushered the stock lower since mid-September.

What a difference a day makes, though. After Friday's steep earnings-induced sell-off, shares of SINA have jumped 8.4% in today's session. The company is reportedly selling a 15-20% stake of its microblogging site Weibo to Alibaba Group. With SINA sporting a healthy short-interest-to-float ratio of 7.6%, today's call volume may simply represent short sellers picking up hedges against their pessimistic positions in light of today's pop.

If this is a case of shorts purchasing options-related insurance, now is an opportune time to do so. The stock's Schaeffer's Volatility Index (SVI) reading of 47% ranks in the 15th percentile of its annual range. Additionally, implied volatility at the aforementioned 52.50-strike call is currently deflated in relation to its 20-day historical (realized) volatility (48% vs. 67.3%) -- both indications options are priced at attractive levels.